Metal complexes of iminohydroxamic acids

ABSTRACT

Complexes of the formula I                    
     where M═Ni, Pd; process for preparing the metal complexes and the use of the complexes obtainable in this way for the polymerization and copolymerization of olefins, for example in suspension polymerization processes, gas-phase polymerization processes and bulk polymerization processes.

The present invention relates to complexes of the formulae I,

where the variables are defined as follows:

Nu is selected from among O, S, N—R⁴*, P—R⁴*,

M is selected from among Ni, Pd;

h is an integer from 0 to 4;

X are identical or different and are selected from among halogen,C₁-C₈-alkyl, C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl and C₆-C₁₄-aryl,

R¹, R⁴, R⁴* are identical or different and are selected from amonghydrogen

C₁-C₁₈-alkyl, substituted or unsubstituted,

C₂-C₁₈-alkenyl, substituted or unsubstituted, which has from one to 4isolated or conjugated double bonds and is bound via a single bond;

C₃-C₁₂-cycloalkyl, substituted or unsubstituted,

C₇-C₁₃-aralkyl,

C₆-C₁₄-aryl, unsubstituted or substituted by one or more identical ordifferent substituents selected from among

C₁-C₁₈-alkyl, substituted or unsubstituted,

C₂-C₁₈-alkenyl, substituted or unsubstituted,

C₃-C₁₂-cycloalkyl,

C₇-C₁₃-aralkyl,

C₆-C₁₄-aryl,

halogen,

C₁-C₆-alkoxy, substituted or unsubstituted,

C₆-C₁₄-aryloxy,

SiR⁵R⁶R⁷ and O—SiR⁵R⁶R⁷;

five- to six-membered nitrogen-containing heteroaryl radicals which maybe unsubstituted or substituted by one or more identical or differentsubstituents selected from among

C₁-C₁₈-alkyl, substituted or unsubstituted,

C₂-C₁₈-alkenyl, substituted or unsubstituted,

C₃-C₁₂-cycloalkyl,

C₇-C₁₃-aralkyl,

C₆-C₁₄-aryl,

halogen,

C₁-C₆-alkoxy,

C₆-C₁₄-aryloxy,

SiR⁵R⁶R⁷ and O—SiR⁵R⁶R⁷;

and are bound via a single bond;

R² is C₆-C₁₄-aryl, unsubstituted or substituted by one or more identicalor different substituents, or a five- to six-memberednitrogen-containing heteroaryl radical, unsubstituted or substituted byone or more identical or different substituents, where the substituentsare as defined above;

R³ is C₁-C₈-alkyl, C₂-C₁₈-alkenyl, substituted or unsubstituted andhaving from one to 4 isolated or conjugated double bonds,C₃-C₁₂-cycloalkyl, substituted or unsubstituted, C₇-C₁₃-aralkyl,C₆-C₁₄-aryl, unsubstituted or substituted by one or more identical ordifferent substituents, or a five- to six-membered nitrogen-containingheteroaryl radical, unsubstituted or substituted by one or moreidentical or different substituents, where the substituents are asdefined above;

where adjacent radicals R¹ to R⁴ may be joined to one another to form a5- to 12-membered ring which may in turn bear substituents selected fromamong C₁-C₈-alkyl, substituted or unsubstituted, C₂-C₈-alkenyl,substituted or unsubstituted and having from one to 4 isolated orconjugated double bonds, C₃-C₁₂-cycloalkyl, substituted orunsubstituted, C₇-C₁₃-aralkyl and C₆-C₁₄-aryl;

L¹ is an uncharged, organic or inorganic ligand,

R⁵ to R⁷ are identical or different and are selected from amonghydrogen, C₁-C₈-alkyl, C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl andC₆-C₁₄-aryl.

The present invention further provides a process for the polymerizationof olefins using complexes of the formula I.

Polymers and copolymers of olefins are of great economic importancebecause the monomers are readily available in large quantities andbecause the polymers can be varied within a wide range by variation ofthe production process or the processing parameters. In the productionprocess, the catalyst used is of particular importance. Apart fromZiegler-Natta catalysts, various types of single-site catalysts are ofincreasing importance, with metals which have been examined in detail ascentral atoms being not only Zr as in metallocene catalysts (H.-H.Brintzinger et al., Angew. Chem. 1995, 107, 1255) but also Ni or Pd (WO96/23010) or Fe and Co (e.g. WO 98/27124). The complexes of Ni, Pd, Feand Co are also referred to as complexes of late transition metals.

Metallocene catalysts have disadvantages for industrial use. The mostfrequently used metallocenes, namely zirconocenes and hafnocenes, aresensitive to hydrolysis. In addition, most metallocenes are sensitivetoward many catalyst poisons such as alcohols, ethers or CO, which makesit necessary for the monomers to be carefully purified.

While Ni or Pd complexes (WO 96/23010) catalyst the formation of highlybranched polymers which are of little commercial interest, the use of Feor Co complexes leads to the formation of highly linear polyethylenewith very small proportions of comonomer.

EP-A 0 874 005 discloses further polymerization-active complexes. Theseare preferably Ti complexes with salicylaldimine ligands. These, too,bear phenyl substituents or substituted phenyl substituents on thealdimine nitrogen (pages 18-23) or else the aldimine nitrogen isincorporated in a 6-membered ring (pages 31-32). However, they generallyproduce low molecular weight polyethylenes which are of limitedsuitability as materials. Furthermore, in all the ligands disclosed inEP-A 0 874 005, the oxygen atom is part of a phenolic system, whichrestricts the choice of readily available starting materials.

U.S. Pat. No. 2001/0025007 discloses compounds of the formulae A and B

and their use as catalysts for the polymerization of olefins, where G²,R and R′ are hydrocarbon radicals, U is a group such as alkoxy and V isselected from among CR, N and PR₂. However, the synthesis of suchcomplexes A and B is rather complicated. In addition, the processengineering parameters of the complexes A and B are capable ofimprovement.

As G. J. P. Britovsek et al. in Angew. Chem. 1999, 111, 448, and Angew.Chem. Int. Ed. Engl. 1999, 38, 428, show, the search for very versatilepolymerization-active complexes continues to be of importance because ofthe great commercial importance of polyolefins. There is interest infinding polymerization-active complexes which have a particularlyadvantageous property profile in process engineering terms.

It is an object of the invention

to provide new complexes which are suitable for the polymerization ofolefins to form high molecular weight polymers;

to provide a process for preparing the complexes of the presentinvention;

to provide a process for the polymerization or copolymerization ofolefins using the complexes of the present invention;

to provide supported catalysts for the polymerization of olefins andalso a process for preparing the supported catalysts of the presentinvention using the complexes of the present invention;

to polymerize and copolymerize olefins using the supported catalysts ofthe present invention.

We have found that this object is achieved by means of complexes whichhave the structures of the formula I defined at the outset.

In formula I, the variables are defined as follows:

Nu is selected from among O, S, N—R⁴* and P—R⁴*, with oxygen and N—R⁴*being preferred;

M is selected from among Ni and Pd in the oxidation state +2,particularly preferably Ni;

h is an integer from 0 to 4, preferably 0;

X are identical or different and are selected from among

halogen, such as fluorine, chlorine, bromine and iodine, preferablychlorine and bromine and particularly preferably chlorine;

C₁-C₈-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl,neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl, sec-hexyl,n-heptyl, isoheptyl and n-octyl; preferably C₁-C₆-alkyl such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl,n-pentyl, isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl,n-hexyl, isohexyl, sec-hexyl, particularly preferably C₁-C₄-alkyl suchas methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl andtert-butyl;

C₃-C₁₂-cycloalkyl, such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl and cyclododecyl; preferably cyclopentyl, cyclohexyl andcycloheptyl;

C₇-C₁₃-aralkyl, preferably C₇-C₁₂-phenylalkyl such as benzyl,1-phenethyl, 2-phenethyl, 1-phenylpropyl, 2-phenylpropyl,3-phenylpropyl, neophyl (1-methyl-1-phenylethyl), 1-phenylbutyl,2-phenylbutyl, 3-phenylbutyl and 4-phenylbutyl, particularly preferablybenzyl; and

C₆-C₁₄-aryl, for example phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl and 9-phenanthryl, preferably phenyl, 1-naphthyl and2-naphthyl, particularly preferably phenyl.

X is preferably halogen.

R¹, R⁴ and R⁴* are identical or different and are selected from among

hydrogen,

C₁-C₁₈-alkyl groups, such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl, n-octyl, n-decyl, n-dodecyl andn-octadecyl; preferably C₁-C₁₂-alkyl such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl,isohexyl, sec-hexyl and n-decyl, particularly preferably C₁-C₄-alkylsuch as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyland tert-butyl;

examples of substituted C₁-C₁₈-alkyl groups are: monohalogenated orpolyhalogenated C₁-C₈-alkyl groups such as fluoromethyl, difluoromethyl,trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl,bromomethyl, dibromomethyl, tribromomethyl, pentafluoroethyl,perfluoropropyl and perfluorobutyl, particularly preferablyfluoromethyl, difluoromethyl, trifluoromethyl and perfluorobutyl;

C₂-C₁₈-alkenyl which has from one to 4 isolated or conjugated doublebonds and is bound via a single bond, for example vinyl, 1-allyl,3-allyl, ω-butenyl, ω-pentenyl, ω-hexenyl, 1-cis-buta-1,3-dienyl and1-cis-hexa-1,5-dienyl;

examples of substituted C₂-C₁₈-alkenyl groups are: isopropenyl,1-isoprenyl, α-styryl, β-styryl, 1-cis-1,2-phenylethenyl or1-trans-1,2-phenylethenyl;

C₃-C₁₂-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl and cyclododecyl; preferably cyclopentyl, cyclohexyl andcycloheptyl;

examples of substituted cycloalkyl groups are: 2-methylcyclopentyl,3-methylcyclopentyl, cis-2,4-dimethylcyclopentyl,trans-2,4-dimethylcyclopentyl, cis-2,5-dimethylcyclopentyl,trans-2,5-dimethylcyclopentyl, 2,2,5,5-tetramethylcyclopentyl,2-methylcyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl,cis-2,6-dimethylcyclohexyl, trans-2,6-dimethylcyclohexyl,cis-2,6-diisopropylcyclohexyl, trans-2,6-diisopropylcyclohexyl,2,2,6,6-tetramethylcyclohexyl, 2-methoxycyclopentyl,2-methoxycyclohexyl, 3-methoxycyclopentyl, 3-methoxycyclohexyl,2-chlorocyclopentyl, 3-chlorocyclopentyl, 2,4-dichlorocyclopentyl,2,2,4,4-tetrachlorocyclopentyl, 2-chlorocyclohexyl, 3-chlorocyclohexyl,4-chlorocyclohexyl, 2,5-dichlorocyclohexyl,2,2,6,6-tetrachlorocyclohexyl, 2-thiomethylcyclopentyl,2-thiomethylcyclohexyl, 3-thiomethylcyclopentyl, 3-thiomethylcyclohexyland further derivatives;

C₇-C₁₃-aralkyl, preferably C₇-C₁₂-phenylalkyl such as benzyl,1-phenethyl, 2-phenethyl, 1-phenylpropyl, 2-phenylpropyl,3-phenylpropyl, neophyl (1-methyl-1-phenylethyl), 1-phenylbutyl,2-phenylbutyl, 3-phenylbutyl and 4-phenylbutyl, particularly preferablybenzyl;

C₆-C₁₄-aryl, for example phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl and 9-phenanthryl, preferably phenyl, 1-naphthyl and2-naphthyl, particularly preferably phenyl;

C₆-C₁₄-aryl such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl and 9-phenanthryl, substituted by one or more identical ordifferent substituents selected from among

C₁-C₁₈-alkyl groups, such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl n-octyl, n-decyl, n-dodecyl andn-octadecyl; preferably C₁-C₁₂-alkyl such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl,isohexyl, sec-hexyl and n-decyl, particularly preferably C₁-C₄-alkylsuch as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyland tert-butyl;

examples of substituted C₁-C₈-alkyl groups are: monohalogenated orpolyhalogenated C₁-C₈-alkyl groups such as fluoromethyl, difluoromethyl,trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl,bromomethyl, dibromomethyl, tribromomethyl, pentafluoroethyl,perfluoropropyl and perfluorobutyl, particularly preferablyfluoromethyl, difluoromethyl, trifluoromethyl and perfluorobutyl;

C₂-C₁₈-alkenyl having from one to 4 isolated or conjugated double bonds,for example vinyl, 1-allyl, 3-allyl, ω-butenyl, ω-pentenyl, ω-hexenyl,1-cis-buta-1,3-dienyl and 1-cis-hexa-1,5-dienyl;

examples of substituted C₂-C₁₈-alkenyl groups are: isopropenyl,1-isoprenyl, α-styryl, β-styryl, 1-cis-1,2-phenylethenyl and1-trans-1,2-phenylethenyl;

C₃-C₁₂-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl and cyclododecyl; preferably cyclopentyl, cyclohexyl andcycloheptyl;

C₇-C₁₃-aralkyl, preferably C₇-C₁₂-phenylalkyl such as benzyl,1-phenethyl, 2-phenethyl, 1-phenylpropyl, 2-phenylpropyl,3-phenylpropyl, neophyl (1-methyl-1-phenylethyl), 1-phenylbutyl,2-phenylbutyl, 3-phenylbutyl and 4-phenylbutyl, particularly preferablybenzyl;

C₆-C₁₄-aryl, for example phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl and 9-phenanthryl, preferably phenyl, 1-naphthyl and2-naphthyl, particularly preferably phenyl;

halogen, for example fluorine, chlorine, bromine and iodine,particularly preferably fluorine and chlorine;

C₁-C₆-alkoxy groups such as methoxy, ethoxy, n-propoxy, isopropoxy,n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, isopentoxy,n-hexoxy and isohexoxy, particularly preferably methoxy, ethoxy,n-propoxy and n-butoxy;

C₆-C₁₄-aryloxy groups such as phenoxy, ortho-cresyloxy, meta-cresyloxy,para-cresyloxy, α-naphthoxy, β-naphthoxy and 9-anthryloxy;

silyl groups SiR⁵R⁶R⁷, where R⁵ to R⁷ are selected independently fromamong hydrogen, C₁-C₈-alkyl groups, the benzyl radical and C₆-C₁₄-arylgroups; preference is given to the trimethylsilyl, triethylsilyl,triisopropylsilyl, diethylisopropylsilyl, dimethylhexylsilyl,tert-butyldimethylsilyl, tert-butyldiphenylsilyl, tribenzylsilyl,triphenylsilyl and tri-para-xylylsilyl groups; particular preference isgiven to the trimethylsilyl group and the tert-butyldimethylsilyl group;

silyloxy groups OSiR⁵R⁶R⁷, where R⁵ to R⁷ are selected independentlyfrom among hydrogen, C₁-C₈-alkyl groups, the benzyl radical andC₆-C₁₄-aryl groups; preference is given to the trimethylsilyloxy,triethylsilyloxy, triisopropylsilyloxy, diethylisopropylsilyloxy,dimethylhexylsilyloxy, tert-butyldimethylsilyloxy,tert-butyldiphenylsilyloxy, tribenzylsilyloxy, triphenylsilyloxy andtri-para-xylylsilyloxy groups; particular preference is given to thetrimethylsilyloxy group and the tert-butyldimethylsilyloxy group;

five- to six-membered nitrogen-containing heteroaryl radicals bound viaa single bond, for example N-pyrrolyl, pyrrol-2-yl, pyrrol-3-yl,N-imidazolyl, 2-imidazolyl, 4-imidazolyl, 1,2,4-triazol-3-yl,1,2,4-triazol-4-yl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 3-pyridazinyl,4-pyridazinyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, N-indolyland N-carbazolyl;

five- to six-membered nitrogen-containing heteroaryl radicals such asN-pyrrolyl, pyrrol-2-yl, pyrrol-3-yl, N-imidazolyl, 2-imidazolyl,4-imidazolyl, 1,2,4-triazol-3-yl, 1,2,4-triazol-4-yl, 2-pyridyl,3-pyridyl, 4-pyridyl, 3-pyridazinyl, 4-pyridazinyl, 2-pyrimidinyl,4-pyrimidinyl, 5-pyrimidinyl, N-indolyl and N-carbazolyl, which arebound via a single bond and are substituted by one or more identical ordifferent substituents selected from among

C₁-C₁₈-alkyl groups, such as methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl,sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl,sec-hexyl, n-heptyl, isoheptyl n-octyl, n-decyl, n-dodecyl andn-octadecyl; preferably C₁-C₁₂-alkyl such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl,isohexyl, sec-hexyl and n-decyl, particularly preferably C₁-C₄-alkylsuch as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyland tert-butyl;

examples of substituted C₁-C₁₈-alkyl groups are: monohalogenated orpolyhalogenated C₁-C₈-alkyl groups such as fluoromethyl, difluoromethyl,trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl,bromomethyl, dibromomethyl, tribromomethyl, pentafluoroethyl,perfluoropropyl and perfluorobutyl, particularly preferablyfluoromethyl, difluoromethyl, trifluoromethyl and perfluorobutyl;

C₂-C₁₈-alkenyl which has from one to 4 isolated or conjugated doublebonds, for example vinyl, 1-allyl, 3-allyl, ω-butenyl, ω-pentenyl,ω-hexenyl, 1-cis-buta-1,3-dienyl and 1-cis-hexa-1,5-dienyl;

examples of substituted C₂-C₁₈-alkenyl groups are: isopropenyl,1-isoprenyl, α-styryl, β-styryl, 1-cis-1,2-phenylethenyl or1-trans-1,2-phenylethenyl;

C₃-C₁₂-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl and cyclododecyl; preferably cyclopentyl, cyclohexyl andcycloheptyl;

C₇-C₁₃-aralkyl, preferably C₇-C₁₂-phenylalkyl such as benzyl,1-phenethyl, 2-phenethyl, 1-phenylpropyl, 2-phenylpropyl,3-phenylpropyl, neophyl (1-methyl-1-phenylethyl), 1-phenylbutyl,2-phenylbutyl, 3-phenylbutyl and 4-phenylbutyl, particularly preferablybenzyl;

C₆-C₁₄-aryl, for example phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl and 9-phenanthryl, preferably phenyl, 1-naphthyl und2-naphthyl, particularly preferably phenyl;

halogen, for example fluorine, chlorine, bromine and iodine,particularly preferably fluorine and chlorine;

C₁-C₆-alkoxy groups such as methoxy, ethoxy, n-propoxy, isopropoxy,n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, isopentoxy,n-hexoxy and isohexoxy, particularly preferably methoxy, ethoxy,n-propoxy and n-butoxy;

C₆-C₁₄-aryloxy groups such as phenoxy, ortho-cresyloxy, meta-cresyloxy,para-cresyloxy, α-naphthoxy, β-naphthoxy and 9-anthryloxy;

silyl groups SiR⁵R⁶R⁷, where R⁵ to R⁷ are selected independently fromamong hydrogen, C₁-C₈-alkyl groups, the benzyl radical and C₆-C₁₄-arylgroups; preference is given to the trimethylsilyl, triethylsilyl,triisopropylsilyl, diethylisopropylsilyl, dimethylhexylsilyl,tert-butyldimethylsilyl, tert-butyldiphenylsilyl, tribenzylsilyl,triphenylsilyl and tri-para-xylylsilyl groups; particular preference isgiven to the trimethylsilyl group and the tert-butyldimethylsilyl group;

silyloxy groups OSiR⁵R⁶R⁷, where R⁵ to R⁷ are selected independentlyfrom among hydrogen, C₁-C₈-alkyl groups, the benzyl radical andC₆-C₁₄-aryl groups; preference is given to the trimethylsilyloxy,triethylsilyloxy, triisopropylsilyloxy, diethylisopropylsilyloxy,dimethylhexylsilyloxy, tert-butyldimethylsilyloxy,tert-butyldiphenylsilyloxy, tribenzylsilyloxy, triphenylsilyloxy andtri-para-xylylsilyloxy groups; particular preference is given to thetrimethylsilyloxy group and the tert-butyldimethylsilyloxy group.

It is preferred that at least one of the radicals R⁴ and R⁴* is nothydrogen. In a particularly preferred embodiment, R¹ or R⁴ is nothydrogen.

R² is C₆-C₁₄-aryl, unsubstituted or substituted by one or more identicalor different substituents, or a five- to six-memberednitrogen-containing heteroaryl radical, unsubstituted or substituted byone or more identical or different substituents, where the substituentsare as defined above.

R³ and R⁸ are identical or different and are selected from amongC₁-C₁₈-alkyl, C₂-C₁₈-alkenyl, substituted or unsubstituted and havingfrom one to 4 isolated or conjugated double bonds, C₃-C₁₂-cycloalkyl,substituted or unsubstituted, C₇-C₁₃-aralkyl, C₆-C₁₄-aryl, unsubstitutedor substituted by one or more identical or different substituents, andfive- and six-membered nitrogen-containing heteroaryl radicals,unsubstituted or substituted by one or more identical or differentsubstituents, where the substituents are as defined above.

In a particularly preferred embodiment, R¹ is 2,6-diisopropylphenyl.

In a particularly preferred embodiment, R² is phenyl.

L¹ is selected from among uncharged, inorganic and organic ligands, forexample from among phosphines of the formula (R⁸)_(x)PH_(3−x) or aminesof the formula (R⁸)_(x)NH_(3−x), where x is an integer from 0 to 3.However, ethers (R⁸)₂O such as dialkyl ethers, e.g. diethyl ether, orcyclic ethers, for example tetrahydrofuran, H₂O, alcohols (R⁸)OH such asmethanol or ethanol, pyridine, pyridine derivatives of the formulaC₅H_(5−x)(R⁸)_(x)N, for example 2-picoline, 3-picoline, 4-picoline,2,3-lutidine, 2,4-lutidine, 2,5-lutidine, 2,6-lutidine or 3,5-lutidine,CO, C₁-C₁₂-alkylnitriles or C₆-C₁₄-arylnitriles, e.g. acetonitrile,propionitrile, butyronitrile or benzonitrile, are also suitable.Furthermore, singly or multiply ethylenically unsaturated double bondsystems, e.g. ethenyl, propenyl, cis-2-butenyl, trans-2-butenyl,cyclohexenyl or norbornenyl, can serve as ligand.

In a particular embodiment, adjacent radicals R¹ to R⁴ or R⁴* in thecomplexes of the formula I may be joined to one another to form a 5- to12-membered ring. For example, R³ and R⁴ may together be: —(CH₂)₃—(trimethylene), —(CH₂)₄— (tetramethylene), —(CH₂)₅— (pentamethylene),—(CH₂)₆— (hexamethylene), —CH₂—CH═CH—, —CH₂—CH═CH—CH₂—, —CH═CH—CH═CH—,—O—CH₂—O—, —O—CHMe—O—, —O—CH—(C₆H₅)—O—, —O—CH₂—CH₂—O—, —O—CMe₂—O—,—NMe—CH₂—CH₂—NMe—, —NMe—CH₂—NMe— or —O—SiMe₂—O— where Me═CH₃.

The complexes of the present invention can be synthesized readily.

The synthesis of the novel complexes of the formula I generally startsout from a ligand of the formula II,

where the variables are as defined above.

The ligands of the formula II are reacted with metal compounds of theformula MX₂. Here, MX₂ may optionally be stabilized by unchargedligands. Possible uncharged ligands are the customary ligands ofcoordination chemistry, for example cyclic and noncyclic ethers, amines,diamines, nitriles, isonitriles or phosphines. Particular preference isgiven to diethyl ether, tetrahydrofuran, 1,2-dimethoxyethane,tetramethylethylenediamine, acetonitrile or triphenylphosphine.

The reaction is carried out in the absence of acids and bases by simplemixing in a solvent. Solvents which have been found to be useful arebenzene, toluene, ortho-xylene, meta-xylene, para-xylene, ethylbenzeneor mixtures thereof, also noncyclic or cyclic ethers such as1,2-dimethoxyethane, tetrahydrofuran or diethyl ether, as well aschlorinated hydrocarbons such as methylene chloride or chloroform.

An appropriate temperature range is from −100° C. to +150° C.,preferably from −78° C. to +100° C. The reaction temperature should notbe below the melting point of the solvent; temperatures above theboiling point of the solvent concerned can be achieved in autoclaves.The reaction is preferably carried out in the absence of oxygen andmoisture.

Suitable molar ratios of ligand to M are in the range from 5:1 to 1:5.However, since the ligands of the formula II are generally the moredifficult-to-obtain reactants, molar ratios of ligand:M in the rangefrom 1:1 to 1:3 are preferred, and particular preference is given tostoichiometric amounts.

The novel complexes of the formula I a are purified by the methodscustomary in organometallic chemistry, with particular preference beinggiven to crystallization and precipitation. Filtration through filteraids such as Celite® is also useful.

The preparation of the ligands of the formula II is known per se and canbe particularly readily carried out by reacting an amide of the formulaIII,

which bears an acidic α-H atom on the nitrogen, with a halogenatingagent such as SO₂Cl₂, PCl₃ or POCl₃ and subsequently reacting theproduct with a nucleophilic compound of the formula IV,

where the variables in the compounds III and IV are as defined above, inthe presence of a base.

Preferred bases are tertiary amines such as triethylamine,diisopropylethylamine or pyridine. Solvents which have been found to beuseful are alcohols or chlorinated hydrocarbons, for example methylenechloride or chloroform, or mixtures thereof, also noncyclic or cyclicethers such as 1,2-dimethoxyethane, tetrahydrofuran or diethyl ether.

This reaction is generally complete after a period of from a few minutesto a few hours; a reaction time of from 30 minutes to 10 hours is usefuland preference is given to from 1 to 5 hours. The temperature conditionsare generally not critical; a temperature range from −90° C. to +30° C.is preferred, in exceptional cases up to 50° C.

The reaction is preferably carried out in the absence of oxygen andmoisture.

Suitable molar ratios of III to IV are in the range from 5:1 to 1:5;preference is given to molar ratios of III:IV in the range from 3:1 to1:3, and stoichiometric amounts are particularly preferred.

It has been found that the novel complexes of the formula I are suitablefor polymerizing olefins. They polymerize and copolymerize ethylene andpropylene particularly readily to form high molecular weight polymers.

For the novel complexes of the formula I to be catalytically active,they have to be activated. Suitable activators for the complexes of theformula I are selected aluminum or boron compounds bearingelectron-withdrawing radicals (e.g. trispentafluorophenylboran,trispentafluorophenylaluminum, N,N-dimethylaniliniumtetrakispentafluorophenylborate, tri-n-butylammoniumtetrakispentafluorophenylborate, N,N-dimethylaniliniumtetrakis(3,5-bisperfluoromethylphenyl)borate, tri-n-butylammoniumtetrakis(3,5-bisperfluoromethylphenyl)borate and trityliumtetrakispentafluorophenylborate). Preference is given todimethylanilinium tetrakispentafluorophenylborate, trityliumtetrakispentafluorophenylborate and trispentafluorophenylborane.

If boron or aluminum compounds are used as activators for the complexesof the present invention, they are generally used in a molar ratio to Mof from 1:10 to 10:1, preferably from 1:2 to 5:1 and particularpreferably in stoichiometric amounts.

Another useful class of activators consists of aluminoxanes. Thestructure of the aluminoxanes is not known precisely. They are productswhich are obtained by careful partial hydrolysis of aluminum alkyls (cf.DE-A 30 07 725). These products are not pure single compounds, butmixtures of open-chain and cyclic structures of the formulae V a and Vb. These mixtures are presumably present in a dynamic equilibrium withone another.

In the formulae Va and Vb,

the radicals R^(m) are each, independently of one another

C₁-C₁₂-alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl,neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl, sec-hexyl,n-heptyl, isoheptyl, n-octyl, n-nonyl, n-decyl or n-dodecyl; preferablyC₁-C₆-alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl,neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl, isohexyl, sec-hexyl,particularly preferably methyl;

C₃-C₁₂-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl,cycloundecyl or cyclododecyl; preferably cyclopentyl, cyclohexyl orcycloheptyl;

C₇-C₂₀-aralkyl, preferably C₇-C₁₂-phenylalkyl such as benzyl,1-phenethyl, 2-phenethyl, 1-phenylpropyl, 2-phenylpropyl,3-phenylpropyl, 1-phenylbutyl, 2-phenylbutyl, 3-phenylbutyl or4-phenylbutyl, particularly prefearbly benzyl, or

C₆-C₁₄-aryl such as phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl,2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl,4-phenanthryl or 9-phenanthryl, preferably phenyl, 1-naphthyl or2-naphthyl, particularly preferably phenyl; and

n is an integer from 0 to 40, preferably from 1 to 25 and particularlypreferably from 2 to 22.

Cage-like structures for aluminoxanes are also discussed in theliterature (Y. Koide, S. G. Bott, A. R. Barron Organometallics 1996, 15,2213-26; A. R. Barron Macromol. Symp. 1995, 97, 15-25). Regardless ofthe actual structure of the aluminoxanes, they are suitable asactivators for the novel metal complexes of the formulae I a and I b.

Mixtures of various aluminoxanes are particularly preferred activatorsin cases in which the polymerization is carried out in solution in aparaffin, for example n-heptane or isododecane. A particularly preferredmixture is the commercially available CoMAO of the formula[(CH₃)_(0.9)(isoC₄H₉)_(0.1)AlO]_(n) obtainable from Witco GmbH.

To activate the complexes of the formula I by means of aluminoxanes, anexcess of aluminoxane over M is generally necessary. Practical molarratios of M:Al are in the range from 1:10 to 1:10000, preferably from1:50 to 1:1000 and particularly preferably from 1:100 to 1:500.

The chosen complex of the formula I and the activator together form acatalyst system.

Addition of further aluminum alkyl of the formula Al(R^(m))₃ oraluminoxanes can increase the activity of the catalyst system of thepresent invention; aluminum alkyls of the formula Al(R^(m))₃ oraluminoxanes can also act as molar mass regulators. A further effectivemolar mass regulator is hydrogen. The molar mass can be regulatedparticularly effectively by means of the reaction temperature and thepressure. If the use of a boron compound as described above is desired,the addition of an aluminum alkyl of the formula Al(R^(m))₃ isparticularly preferred.

Pressure and temperature conditions during the polymerization can beselected within wide limits. A pressure range which has been found to beuseful is from 0.5 bar to 4000 bar, preferably from 10 to 75 bar orhigh-pressure conditions of from 500 to 2500 bar. A useful temperaturerange has been found to be from 0 to 120° C., preferably from 40 to 100°C. and particularly preferably from 50 to 85° C.

Suitable monomers include the following olefins: ethylene, propylene,1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and 1-undecene, withpropylene and ethylene being preferred and ethylene being particularlypreferred. A further suitable monomer is styrene.

Suitable comonomers include α-olefins, for example from 0.1 to 20 mol %of 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-deceneor 1-undecene. However, isobutene and styrene are also suitablecomonomers, also internal olefins such as cyclopentene, cyclohexene,norbornene and norbornadiene, or from 0.1 to 50 mol % of carbonmonoxide.

Apart from other α-olefins, for example propene, 1-butene, 1-hexene,1-octene or 1-decene, as comonomers, polar comonomers can also beincorporated with the aid of the catalyst system of the presentinvention. From 0.1 to 50 mol % of comonomer can be used. Preference isgiven to

acrylates such as acrylic acid, methyl acrylate, ethyl acrylate,2-ethylhexyl acrylate, n-butyl acrylate or tert-butyl acrylate;

methacrylic acid, methyl methacrylate, ethyl methacrylate, n-butylmethacrylate or tert-butyl methacrylate;

vinylaromatic compounds such as styrene;

vinyl carboxylates, with vinyl acetate being particularly preferred,

unsaturated dicarboxylic acids, particularly preferably maleic acid,

unsaturated dicarboxylic acid derivatives, particularly preferablymaleic anhydride and alkylimides of maleic acid, for example maleic acidmethylimide.

Furthermore, terpolymers comprising at least 2 of the abovementionedmonomers together with ethylene can also be prepared.

Solvents which have been found to be useful are toluene, ortho-xylene,meta-xylene, para-xylene or ethylbenzene and mixtures thereof, also,under high-pressure conditions, supercritical ethylene.

The catalyst systems of the present invention polymerize olefins to givepolyolefins having a very high molecular weight.

The polymerization using the catalyst systems of the present inventioncan be regulated by means of hydrogen, i.e. addition of hydrogen enablesthe molecular weight of the polymers obtainable by means of the catalystsystem of the present invention to be reduced. If sufficient hydrogen isadded, polyolefin waxes are obtained. The preferred concentration of thehydrogen is also dependent upon the type of polymerization plantemployed.

For the catalyst systems of the present invention to be able to be usedin modern polymerization processes such as suspension processes, bulkpolymerization processes or gas-phase processes, it is necessary forthem to be immobilized on a solid support. Otherwise, problems withpolymer morphology (lumps, deposits on walls, blockages in lines or heatexchangers) can occur and force shutdown of the plant. Such animmobilized catalyst system is referred to as catalyst.

The catalyst systems of the present invention can be deposited on solidsupport materials. Suitable support materials are, for example, porousmetal oxides of metals of groups 2 to 14 or mixtures thereof, also sheetsilicates and zeolites. Preferred examples of metal oxides of groups 2to 14 are SiO₂, B₂O₃, Al₂O₃, MgO, CaO and ZnO. Preferred sheet silicatesare montmorillonites or bentonites; a preferred zeolite is MCM-41.

Particularly preferred support materials are spherical silica gels andaluminosilicate gels of the formula SiO₂ a Al₂O₃, where a is generallyin the range from 0 to 2, preferably from 0 to 0.5. Such silica gels arecommercially available, e.g. silica gel SG 332, Sylopol® 948 or 952 or S2101 from W. R. Grace or ES 70X from Crosfield.

As particle size of the support materials, mean particle diameters offrom 1 to 300 μm, preferably from 20 to 80 μm, have been found to beuseful, with the particle diameter being determined by known methodssuch as sieve methods. The pore volume of the supports is from 1.0 to3.0 ml/g, preferably from 1.6 to 2.2 ml/g and particularly preferablyfrom 1.7 to 1.9 ml/g. The BET surface area is from 200 to 750 m²/g,preferably from 250 to 400 m²/g.

To remove impurities, in particular moisture, adhering to the supportmaterial, the support materials can be baked out, e.g. at from 45 to1000° C., prior to doping. Temperatures of from 100 to 750° C. areparticularly suitable for silica gels and other metal oxides. Thisbaking can be carried out from a period of from 0.5 to 24 hours,preferably from 1 to 12 hours. The pressure conditions are dependent onthe process chosen; baking can be carried out in a fixed bed, in astirred vessel or else in a moving bed. Baking can generally be carriedout at atmospheric pressure. However, reduced pressures of from 0.1 to500 mbar are advantageous, a pressure range from 1 to 100 mbar isparticularly advantageous and a range from 2 to 20 mbar is veryparticularly advantageous. On the other hand, moving-bed processes areadvantageously carried out at slightly superatmopsheric pressure in therange from 1.01 bar to 5 bar, preferably from 1.1 to 1.5 bar.

Chemical pretreatment of the support material with an alkyl compoundsuch as an aluminum alkyl, lithium alkyl or an aluminoxane is likewisepossible.

A polymerization by the suspension method is carried out usingsuspension media in which the desired polymer is insoluble or onlyslightly soluble, because otherwise deposits of the product occur inplant components in which the product is separated from the suspensionmedium and force repeated shutdowns and cleaning operations. Suitablesuspension media are saturated hydrocarbons such as propane, n-butane,isobutane, n-pentane, isopentane, n-hexane, isohexane and cyclohexane,with isobutane being preferred.

Pressure and temperature conditions during the polymerization can beselected within wide limits. A useful pressure range has been found tobe from 0.5 bar to 150 bar, preferably from 10 to 75 bar. A usefultemperature range has been found to be from 0 to 120° C., preferablyfrom 40 to 100° C.

Suitable monomers include the following olefins: ethylene, propylene,1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene and 1-undecene.

Suitable comonomers include α-olefines, for example from 0.1 to 20 mol %of 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-deceneor 1-undecene. However, isobutene and styrene are also suitablecomonomers, also internal olefins such as cyclopentene, cyclohexene,norbornene and norbornadiene. From 0.1 to 50 mol % of carbon monoxide isalso suitable.

The catalysts of the present invention have an overall property profilewhich is advantageous in process engineering terms.

Furthermore, hydrogen has been found to be useful as chain transferagent in polymerizations using the catalysts of the present invention,i.e. the molecular weight of the polymers obtainable by means of thecatalyst of the present invention can be reduced by addition ofhydrogen. If sufficient hydrogen is added, waxes are obtained; thehydrogen concentration required also depending on the type ofpolymerization plant employed. The addition of hydrogen generallyincreases the activity of the catalysts of the present invention.

The catalysts of the present invention can also be used together withone or more polymerization catalysts known per se. Thus, they can, forexample, be used together with

Ziegler-Natta catalysts,

supported metallocene catalysts containing transition metals of groups 4to 6 of the Periodic Table of the Elements,

catalysts containing late transition metals (WO 96/23010),

Fe or Co complexes with pyridyldiimine ligands as are disclosed in WO98/27124,

or chromium oxide catalysts of the Phillips type.

It is possible to mix various catalysts with one another and meter themin together or to use cosupported complexes on a common support or tometer various catalysts separately into the polymerization vessel at thesame place or at different places.

The following examples illustrate the invention.

General Preliminary Remarks:

All work was, unless indicated otherwise, carried out with exclusion ofair and moisture using standard Schlenk techniques. Apparatus andchemicals were prepared appropriately. The polymer viscosity wasdetermined in accordance with ISO 1628-3.

1. Preparation of the Ligands

1.1. Preparation of Ligand II.1

The synthesis of the protonated ligands is illustrated by way of exampleby the description of the synthesis of II.1.

a) 1.98 g of N-(2,6-diisopropylphenyl)benzamide (7.0 mmol) III.1 wereplaced in a dry Schlenk tube which had been flushed with argon. Afteraddition of 10 ml of thionyl chloride (137 mmol), the reaction solutionwas refluxed for 60 minutes. Excess SOCl₂ was distilled off under a highvacuum, and the yellow oil which remained was dissolved in 20 ml ofmethylene chloride (absolute).

b) The yellow N,O-dimethylhydroxylamine hydrochloride (0.78 g, 8.0 mmol)was placed in a baked-out Schlenk tube which had been flushed withargon, dissolved in absolute ethanol (50 ml) and activated with 2.2 mlof triethylamine (16 mmol).

The imide chloride III.1 prepared as described in a) and dissolved inmethylene chloride was added slowly from a dropping funnel to thesolution b) at −45° C. over a period of 45 minutes. After warming toroom temperature, the reaction solution was stirred for 1 hour (colorchange: greenish→lemon yellow). Subsequent thin layer chromatography(diethyl ether/n-hexane=1/1) was no longer able to detect any III.1.

The reaction solution was poured into water (about 100 ml) and theproduct was extracted 3 times with 50 ml each time of diethyl ether. Thecombined organic phases were dried over Na₂SO₄ and the dessicant wasfiltered off. After the solvent had been taken off on a rotorevaporator, the resulting viscous oil was dried in a high vacuum.

Yield: 2.11 g (93%), empirical formula: C₂₁H₂₈N₂O, color: brown

¹H-NMR (CDCl₃): 0.91 (6H, d, CH(CH ₃)₂, J=7.0 Hz), 1.06 (6H, d, CH(CH₃)₂, J=7.0 Hz), 2.89 (2H, sept, 2×CH(CH₃)₂, J=7.0 Hz), 3.15 (3H, s,N—CH₃), 3.49 (3H, s, O—CH₃), 6.82-6.89 (3H, m, phenyl), 7.13 (5H, s,phenyl).

¹³C-NMR (CDCl₃): 21.9, 23.9 (CH(CH₃)₂), 28.0 (CH(CH₃)₂), 37.0 (N—CH₃),60.2 (O—CH₃), 122.4, 122.5, 127.5, 128.1, 128.8 (C-phenyl), 137.1(C═N-C, quaternary C, phenyl), 144.0 (C═N).

IR (KBr, cm⁻¹): 2962 (m), 2931 (m), 1634 (vs), 1602 (m), 1590 (m), 1461(m), 1436 (m), 1360 (w), 1324 (m), 1256 (w), 1181 (w), 1104 (m), 1057(w), 1030 (w), 1007 (m), 778 (m), 760 (m), 722 (w), 700 (vs).

MS (EI): M⁺=324.3 m/e

EXAMPLE 1.2

Preparation of Ligand II.2

The symmetrically substituted N,N′-dimethylhydrazine hydrochloride (0.55g, 4.1 mmol) was placed in a baked-out Schlenk tube which had beenflushed with argon and suspended in 20 ml of methylene chloride (abs.).The addition of 1.73 ml of triethylamine (12.4 mmol) resulted in aturbid, milky solution.

After the reaction solution had been cooled to −70° C., 10 ml ofcompound III.1 (stock solution, c=0.108 g/ml) were slowly added from adropping funnel over a period of 30 minutes. The initially orangesolution became yellow over a period of 5 minutes after removal of thecold bath. The N,N′-dimethylhydrazine went completely into solution, andthe reaction was complete after 1 hour at room temperature, asdemonstrated by thin layer chromatography.

The reaction solution was poured into water (about 100 ml), and theproduct was extracted 3 times with 50 ml each time of diethyl ether. Toachieve better phase separation, 50 ml of saturated sodium chloridesolution were added. The combined organic phases were dried over Na₂SO₄and the dessicant was filtered off. After the solvent had been removedon a rotary evaporator, the resulting viscous oil was dried in a highvacuum. Attempts to precipitate the target product from ether/hexanemixtures failed, but an analytically pure, pulverulent, brown solid wasobtained after taking off the solvent (firstly ether, then hexane) overa period of 30 minutes.

Yield: 1.10 g (94%), empirical formula: C₂₁H₂₉N₂O, color: brown

¹H-NMR (CDCl₃): 0.94 (6H, d, CH(CH ₃)₂, J=7.0 Hz), 1.06 (6H, d,CH(CH₃)₂, J=6.6 Hz), 2.64 (3H, s, CH ₃—NH), 2.90 (3H, s, N—CH₃), 2.94(2H, sept, 2×CH(CH₃)₂), 6.78-6.86 (3H, m, phenyl), 7.01-7.14 (5H, m,phenyl).

¹³C NMR (CDCl₃): 21.8, 24.1 (CH(CH₃)₂), 28.1 (CH(CH₃)₂), 36.4 (NH—CH₃),39.2 (N—CH₃), 122.1, 122.2, 127.8, 128.1, 128.8, 133.1, 138.2(C-phenyl), 144.7 (C═N—C, quaternary C, phenyl), 157.3 (C═N).

IR (KBr, cm³¹ ¹): 3244 (w), 3062 (w), 3022 (w), 2973 (m), 2960 (m), 1609(vs), 1596 (s), 1586 (vs), 1576 (s), 1492 (w), 1439 (m), 1382 (m), 1364(s), 1329 (m), 1262 (m), 1183 (w), 1111 (m), 1069 (s), 1046 (m), 1025(s), 924 (m), 845 (s), 824 (m), 808 (w), 799 (m), 772 (vs), 760 (vs),714 (vs), 700 (vs)

MS (EI): M⁺=323.3 m/e

EXAMPLE 1.3

Preparation of Ligand II.3

Commercial N,N-dimethylhydrazine (0.58 ml, 0.46 g, 7.7 mmol) was placedin a baked-out Schlenk tube which had been flushed with argon and wasdissolved in absolute ethanol (50 ml).

The III.1 dissolved in methylene chloride (10 ml, 1.08 g, 3.6 mmol,c=0.115 g/ml) was slowly added at −45° C. from a dropping funnel over aperiod of 60 minutes. After warming to room temperature, the reactionsolution was stirred for 1 hour (color change: colorless→yellow). Thehydrazinium salt formed in the reaction precipitated and a turbidsuspension was obtained. The reaction was monitored by thin layerchromatography (diethyl ether/hexane=1/1).

The reaction solution was poured into water (about 100 ml), and theproduct was extracted 3 times with 50 ml each time of diethyl ether. Thecombined organic phases were dried over Na₂SO₄ and the dessicant wasfiltered off. After the solvent had been taken off on a rotaryevaporator, the resulting viscous oil was dried in a high vacuum.

Yield: 1.15 g (99%), empirical formula: C₂₁H₂₉N₃, color: brown

¹H-NMR (CDCl₃): 0.88 (6H, d, CH(CH ₃)₂, J=6.9 Hz), 1.10 (6H, d, CH(CH₃)₂, J=6.9 Hz), 2.57 (6H, s, N(CH ₃)₂), 3.13 (2H, sept, 2×CH(CH₃)₂,J=6.9 Hz), 6.98 (2H, pseudo-d, phenyl), 7.07-7.21 (6H, m, phenyl), 7.95(1H, s, N—H)

¹³C-NMR (CDCl₃): 21.9, 24.9 (CH(CH₃)₂), 26.3 (CH(CH₃)₂), 46.7 (N(CH₃)₂),123.3, 126.9, 127.6, 128.5, 129.1 (C-phenyl), 132.9, 134.3(aniline-C(2,6), quaternary C), 145.2 (C═N—C, quaternary C, phenyl),159.7 (C═N)

TABLE 1 Overview of the ligands of the formula II Compound R¹ R² R³ R⁴Nu II.1 2,6-(i-C₃H₇)₂C₆H₃ C₆H₅ CH₃ CH₃ O II.2 2,6-(i-C₃H₇)₂C₆H₃ C₆H₅ CH₃CH₃ N—H II.3 2,6-(i-C₃H₇)₂C₆H₃ C₆H₅ CH₃ H N—CH₃

i-C₃H₇: isopropyl

2. Syntheses of Complexes of the Formula I

2.1. Synthesis of the Complex I.1

In a baked-out Schlenk tube which had been flushed with argon, theligand II.1 (0.97 g, 3.0 mmol) was dissolved in 20 ml of methylenechloride (absolute), and, after addition of thedimethoxyethane-stabilized transition metal halide (NiBr₂×2 DME, 1.25 g,3.1 mmol), the mixture was stirred at room temperature. The followingcolor changes were observed: yellowish→turbid orange (after 10 s)→turbidbrown (after ½ min)→turbid green. After 10 minutes, a dark greensuspension whose color remained unchanged even after stirring for 48hours was obtained.

After addition of 60 ml of methylene chloride (absolute), the slightexcess of unreacted NiBr₂×2 DME was separated off by filtration (G4frit, without Celite®). The clear, dark green filtrate was evaporated todryness in a high vacuum. A pulverulent green complex I.1 was isolated.

Yield: 1.53 g (94%), empirical formula: C₂₁H₂₈Br₂N₂NiO, color: green

¹H-NMR (CD₂Cl₂): weakly paramagnetic, 1.10-1.49 (12H, m, 2×CH(CH ₃)₂),2.97-3.56 (8H, m, 2×CH(CH₃)₂, N—CH ₃, O—CH ₃)

EXAMPLE 2.2

Synthesis of the Complex I.2

Example 2.1 was repeated using the ligand II.2

Yield: 0.70 g (95%), empirical formula: C₂₁H₂₉Br₂N₃Ni, color: beige1H-NMR (CD₂Cl₂): 1.76, 5.16, 5.41, 15.38, 19.63, 22.57, compound isparamagnetic and no assignment can be made.

EXAMPLE 2.3.

Synthesis of the Complex I.3

Example 2.1 was repeated using ligand II.3

Yield: 0.66 g (76%), empirical formula: C₂₁H₂₉Br₂N₃Ni, color: beige

¹H-NMR (CD₂Cl₂): 0.89-2.04 (12H, m, 2×CH(CH ₃)₂), 3.48 (2H, s, broad,2×CH(CH ₃)₂), 6,00 (6H, s, broad, N(CH₃)₂), 7,11-8,96 (8H, m, phenyl).The signals are broad and shifted to low field. The complex is slightlyparamagnetic.

¹³C-NMR (CD₂Cl₂): 13.1, 21.8, 22.2, 24.7, 29.8, 30.7 (CH(CH₃)₂,CH(CH₃)₂), 50.8 (N—CH₃), 124.0, 126.0, 127.7, 129.7, 131.2, 131.7, 135.5(C-phenyl), 140.0 (C═N—C, quaternary C, phenyl), 143.8 (C═N).

TABLE 2 Overview of the novel complexes of the formula I Com- pound R¹R² R³ R⁴ Nu X M I a.1 2,6-(i-C₃H₇)₂C₆H₃ C₆H₅ CH₃ CH₃ O Br Ni I a.22,6-(CH₃)₂C₆H₃ C₆H₅ CH₃ CH₃ N—H Br Ni I a.3 2-(C₆H₅)—C₆H₄ C₆H₅ CH₃ HN—CH₃ Br Ni i-C₃H₇: isopropyl; p-CH₃—C₆H₄: para-tolyl

3. Polymerization Experiments

3.1. Polymerization in an Autoclave

The indicated amount of the complex to be examined, 2 ml of 30% strengthby weight MAO solution in toluene (commercially available from Witco)and 400 ml of toluene were placed in a 1 l steel autoclave which hadbeen made inert. At 70° C., the autoclave was pressurized with ethyleneto a pressure of 40 bar. This pressure was kept constant over the 90minutes of the test by metering in further amounts of ethylene. Thereaction was stopped by venting and the polymer was isolated byfiltration, subsequent washing with methanol and drying under reducedpressure.

TABLE 3 Polymerization results Ethylene polymerization (40 bar) Weightof complex Activity Yield η Time used Complex [gmmol⁻¹h⁻¹bar⁻¹] [g][dl/g] [min] [mg] I.1 302.8 7.25 3.62 5 3.9 I.2 3.3 1.0 2.15 90 2.7 I.38.4 1.3 2.57 90 1.4 3.3 Ethylene/hexene copolymerization

The procedure of 3.1 was repeated but 12.5 ml of 1-hexene were added tothe autoclave at the beginning together with the other reagents.

TABLE 4 Copolymerization results Copolymerization (ethene/hexene, 40bar) Weight of 1-Hexene complex Com- addition Activity Yield η Time usedplex [ml] [gmmol⁻¹h⁻¹bar^(−1]) [g] [dl/g] [min] [mg] I.1 12.5 1.8 0.7 —90 3,6

We claim:
 1. A complex of the formula I,

wherein Nu is selected from the group consisting of O, S, N—R⁴*, andP-R⁴*; M is Ni or Pd; h is an integer from 0 to 4; X are the same ordifferent and are selected from the group consisting of a halogen,C₁-C₈-alkyl, C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl and C₆-C₁₄-aryl, R¹, R⁴,R⁴* are the same or different and are selected from the group consistingof hydrogen, substituted or unsubstituted C₁-C₁₈-alkyl, substituted orunsubstituted C₂-C₁₈-alkenyl comprising from one to 4 isolated orconjugated double bonds and is bound via a single bond, substituted orunsubstituted C₃-C₁₂-cycloalkyl, C₇-C₃-aralkyl, unsubstituted orsubstituted C₆-C₁₄-aryl, and unsubstituted or substituted five- tosix-membered nitrogen-containing heteroaryl radicals which are bound viaa single bond; R² is an unsubstituted or substituted C₆-C₁₄-aryl, or anunsubstituted or substituted five- to six-membered nitrogen-containingheteroaryl radical; R³, R⁸ are each selected from the group consistingof C₁-C₁₈-alkyl, substituted or unsubstituted C₂-C₁₈-alkenyl comprisingfrom one to 4 isolated or conjugated double bonds, substituted orunsubstituted C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl, unsubstituted orsubstituted C₆-C₁₄-aryl, or a unsubstituted or substituted five- tosix-membered nitrogen-containing heteroaryl radical; wherein adjacentradicals R¹ to R⁴ or R⁴* may be joined to one another to form a 5- to12-membered ring which may comprise a substituent selected from thegroup consisting of substituted or unsubstituted C₁-C₈-alkyl,substituted or unsubstituted C₂-C₈-alkenyl comprising from one to 4isolated or conjugated double bonds, substituted or unsubstitutedC₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl, and C₆-C₁₄-aryl; L¹ is an uncharged,organic or inorganic ligand.
 2. The complex as claimed in claim 1,wherein Nu is oxygen, M is Ni and X is halogen and L¹ is selected fromthe group consisting of phosphines (R⁸)_(x)PH_(3-x), amines(R⁸)_(x)NH_(3-x), ethers (R⁸)₂O, H₂O, alcohols (R⁸)OH, pyridine,pyridine derivatives of the formula C₅H_(5-x)(R⁸)_(x)N, CO,C₁-C₁₂-alkylnitriles, C₆-C₁₄-arylnitriles, and ethylenically unsaturateddouble bond systems, wherein x is an integer from 0 to 3; and R⁸ areidentical or different and are selected from the group consisting ofC₁-C₁₈-alkyl, substituted or unsubstituted C₂-C₁₈-alkenyl comprisingfrom one to 4 isolated or conjugated double bonds, substituted orunsubstituted C₃-C₁₂-cycloalkyl, C₇-C₁₃-aralkyl, unsubstituted orsubstituted C₆-C₁₄-aryl, and unsubstituted or substituted five- tosix-membered nitrogen-containing heteroaryl radicals, wherein thesubstituents are the same or different and selected from the groupconsisting of C₁-C₁₈-alkyl, C₂-C₁₈-alkenyl, C₃-C₁₂-cycloalkyl,C₇-C₁₃-aralkyl, C₆-C₁₄-aryl, halogen, C₁-C₆-alkoxy, C₆-C₁₄-aryloxy,SiR⁵R⁶R⁷ and O—SiR⁵R⁶R⁷.
 3. The complex as claimed in claim 1, wherein his
 0. 4. The complex as claimed in claim 3, wherein h is
 0. 5. Thecomplex as claimed in claim 1, wherein X is a halogen.
 6. The complex asclaimed in claim 1, wherein R¹ is 2,6-diisopropylphenyl.
 7. The complexas claimed in claim 1, wherein R² is phenyl.
 8. A composition comprisingthe complex as claimed in claim 1 immobilized on a solid support.
 9. Acomposition comprising the complex as claimed in claim 2 immobilized ona solid support.
 10. A composition comprising the complex as claimed inclaim 3 immobilized on a solid support.
 11. A composition comprising thecomplex as claimed in claim 4 immobilized on a solid support.
 12. Acomposition comprising the complex as claimed in claim 5 immobilized ona solid support.
 13. A composition comprising the complex as claimed inclaim 6 immobilized on a solid support.
 14. A composition comprising thecomplex as claimed in claim 7 immobilized on a solid support.